Taiwania, 55(2): 123-127, 2010 Acanthocephalan Fauna of Marine Fish in Taiwan and the Differentiation of Three Species by Ribosomal DNA Sequences Hsiu-Hui Shih(1,2*), Hui-Yu Chen(2) and Chew-Yuen Lee(1) 1. Department of Life Science, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617 Taiwan. 2. Institute of Zoolog, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617 Taiwan. * Corresponding author. Tel: +886-2-3366-2504; Email:
[email protected] (Manuscript received 2 December 2009; accepted 9 March 2010) ABSTRACT: Three Acanthocephala species were recovered and identified from three species of fish host. They are Neoechinorhynchus agilis collected from grey mullet, (Mugil cephalus), Neorhadinorhynchus macrospinosus from rabbit fish (Siganus fuscescens), and Rhadinorhynchus pristis from spotted mackerel (Scomber australasicus). All are new locality records. Scanning electron microscopy and light microscopy were used to describe the morphological characters. In addition, these three acanthocephalans were characterized genetically using a molecular approach. The nuclear ribosomal DNA region spanning the first internal transcribed spacer (ITS-1), the 5.8S gene and the second internal transcribed spacer (ITS-2) was amplified and the sizes of PCR products derived were different in length. They are 450 bp for N. agilis, 800 bp for N. macrospinosus, and 600 bp for R. pristis. KEY WORDS: Acanthocephalans, marine fish, Neoechinorhynchus, Neorhadinorhynchus, Rhadinorhynchus. Adult acanthocephalans that infect fish as definitive INTRODUCTION hosts belong to two Classes, Eoacanthocephala and Acanthocephalans, known as thorny-headed worms Palaeacanthocephala. The former includes two Orders: or spiny-headed worms, characterized by the presence of Cyracanthocephala and Neoacanthocephala; and the latter an evertable proboscis, armed with spines, which they consists of two Orders: Echinorhynchidea and use to pierce and hold the gut wall of their gnathostome Polymorphida (Amin, 1987).